I'm about to take my first RV trip in my 1990 Fleetwood Flair but want to try to fix one more thing. My coach had a Aqua Magic Toilet Model: SH and for the life of me, I cant figure out how to get it loose to replace a part inside. I cant get to it from the bottom of the coach. Its bolted down from the top but have no clue where to start. My problem is that is has low flush water pressure and its not holding any water very long. I have manuals i downloaded but they all show a piece that is removable on the top back but mine is a solid piece. I'd like to get it fixed before I leave but it is functional at this point. Any help please?